Valve for engines



PATENTED SEPT. 20, 1904.

J. B. ALLFREE. VALVE FOR ENGINES APPLICATION FILED JULY 30, 1904.

2 SHEETS-SHEET 1' NO MODEL.

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luvemtoz Ham 9 wit" wow 63am PATENTED SEPT. 20 1904.. B. ALLFREB.

VALVE FOR ENGINES.

APPLICATION FILED JULY 30. 1904.

2 SHEETS-SHEET 2.

NO MODEL.

LILIIIII Wat mono G MZ W UNTTED STATES Patented September 20, 190-1.

JAMES B. ALLFREE, OF IRONTON, OHIO.

VALVE FOR ENGlNES.

SPECIFICATION forming part of Letters Patent No. 770,671, datedSeptember 20, 1904.

Application filed July 30, 1904. Serial No. 218,852. (No model.)

To all whom, it may concern.-

Be it known that 1, JAMES B. ALLFREE, a

citizen of the United States, residing at Ironton, in the county ofLawrence and State of Ohio, have invented certain new and usefulImprovements in Valves for Engines, of which the following is aspecification.

My invention relates to improvements in valves for steam-engines orother engines of a similar type.

The objects of my invention are, first, to so construct and arrange acylinder, steam-chest, short live-steam or exhaust ports, and auxiliaryexhaust-ports with cooperating main and compression-regulating valves inorder to insure a more economical distribution and use of the steam inthe cylinder by having the events of the valves or the admission,exhaust, and compression of the steam give the highest rate ofexpansion, greatest mean effective pressure with relatively low terminalpressure at exhaust for a given cut-off and cylinder temperature, and atthe same time attain a most important feature by securing a minimumclearance both in the cylinder and the connecting parts, which willprovide compression sufficient for the proper cushioning and efficientoperation of the piston within the cylinder; second, to construct andarrange a cylinder and steam-chest with the connected livesteam andexhaust ports, which will prevent to the greatest extent radiation ofheat, thereby tending to hold all the heat units of the live steam,preserve the mean cylinder temperature at the highest degree attainable,and reduce condensation in the cylinder, steamchest, and connected portsto a minimum; third, to provide a cylinder and steam-chest withconnecting live-steam and exhaust ports, which in length, condensing,and frictional surfaces are reduced to a minimum and also so arrangedthat the passages leading the live steam to the cylinder are within thespace surrounded by the exhaust steam passages; fourth, to construct amain valve in relation to the details of the cylinder, steam-chest, andports in order that its seat may always be lubricated, the valve at thesame time being exceptionally light in weight and balanced, so as toadapt it particularly for high-speed work,

and at the same time arranged to readily recede from its seat or floatwhile drifting when used in connection with locomotive-cylinders havinglow clearance and compression-regulating valves; fifth, to provide acompression controlling or regulating valve which will open for exhaustsimultaneous with or a little later than the main valve, but made toclose for compression much later than the main valve; sixth, to providean arrangement by which the compression may be varied or regulatedindependently of the main valve by separate adjustment of thecompression controlling or regulating valve and also means whereby theregulation may be controlled Within or out of the cab and while inoperation when used in connection with a locomotive-engine; seventh,other evident functions and advantages of the specific construction andarrangement of the parts, which will hereinafter appear from thedetailed description of the invention and the manner of applying thesame.

My invention comprises novel features of construction and relativearrangements of the parts, which will be hereinafter described in thedetailed description, and particularly pointed out in the appendedclaims.

Reference is had to the accompanying two sheets of drawings, forming apart of this specification, in which similar reference charactersindicate corresponding parts throughout the several figures.

Figure 1 is a longitudinal section on line as w of Fig. 2 of thecylinder, steam-chest, and valves of my invention as applied to alocomotive. Fig. 2 is a transverse section on the line y y of Fig. l ona reduced scale from that shown in Fig. ll Fig. 3 is a plan view withthe steam-chest cover and main valve removed and showing in dotted linesthe relation of the compression-regulating valve, the live-steam andexhaust ports with the cylinder, and their main inlet and exhaustconnections.

In the use of steam in the cylinder of a reciprocating steam-engine,whether it be used as a locomotive, stationary, or marine, it iswell-known that-the steam required to fill the clearance-space, whichcomprises all the volume of the ports and cylinder between the pistonand valve when the piston is at the extreme limit of its movement orstroke, is detrimental to the economy of the engine, and aside from thelittle space necessary for striking room may be said to be waste. It iswell known that in the use of any sort of variablestroke slide-valve aconsiderable amount of clearance-space must be provided for, for thereason that any valve of this class when operated so as to provide anearly cut-off will close the exhaust-port far too soon, especially so ifit is providedwith sufiicient exhaust-lap to retain the steam in thecylinder until its maximum expansion is obtained. The steam or vaporthus entrapped will be compressed by the piston ofttimes considerably inexcess of the'boilerpressure constituting negative work, thus deprivingthe engine of its normal power and creating undue vibration, increasingthe cost of running repairs, as well as creating greater liability foraccident. The means employed by my invention to overcome thesedifficulties and effect the objects stated above will now bespecifically described as used in connection with a locomotive, andwhile so described I wish it to be distinctly understood I do not careto limit myself to this specific use, as will be readily understood bythose skilled in the art. It may be applied to other forms of engineas,for example, stationary or marine type.

Referring to the drawings, 1 is a cylinder which is provided with theusual heads, stuffing-box, threaded openings for drain-valves, and otheressentials, which need no description to be fully understood.

2 is a piston provided with a piston-rod 3, connected to the cross-head4:, which is supported and guided by suitable rods 5 5 in the well-knownmanner.

6 is a steam-chest, preferablylocated above the cylinder and partiallysurrounding or jacketing the cylinder 1. The wall 7 between the chestand cylinder is of suflicient thickness to confine the pressure thereinand resist the stresses to which it may be subjected.

8 8 are short ports passing through the wall 7 at the ends of thecylinder.

6 is a cover of the steam-chest and secured by bolts in the usualmanner.

The specific construction and relation of the cylinder with its shortports for reducing the clearance and efficiently conveying the livesteam to the steam-chest, main valve, and the interior of the cylinder,and finally leading the exhaust-steam to the atmosphere, form one of theimportant features of this invention and will be hereinafter fullydescribed.

13 is a pressure-plate, preferably constructed with double wallsprovided-with intervenis provided at the two sides corresponding to Ithe length of the steam -chest with lugs 14, (see Fig. 2),through whichscrews 15 take into the valve-seat 10, whereby the side fittingstrips 1616, which extend the full length of the pressure-plate and fit insuitable recesses therein, are firmly held between the seat andpressure-plate. As will be seen in referring to Fig. 2, thefitting-strips 16 extend into rectangular recesses in the pressure-plate13 to such a depth that the line of their inner vertical surfacesintersect with the inner wall of the pressure-plate, which is preferablyan arc of a true circle, so that it may be bored out on an ordinaryengine-lathe, and thereby cheapen its manufacture. The valve-chamberthus formed with the valve-seat below, the pressure-plate above, and thefitting-strips at the sides comprises in cross-section the arc of a truecircle, a baseline represented by the valve-seat at a suitable distancebelow and parallel with the cord-line proper of the arc, and thevertical sides bounded by the fitting-strips.

9 is a main valve sliding on the valve-seat 10 in the above-describedvalve-chamber. This valve is preferably of the piston type, formed withtwo end pieces or heads 12 12, which with suitable packing form a tightjoint with the pressure-plate and register with and control the ports 88. 11 is a hollow rod or central tie-section connecting the ends orheads of the valve, by which arrangement I am enabled to construct avery light valve.

While I have herein shown and describeda main slide-valve having twosections connected together for controlling the admission and exhaustports, it can'be readily seen,and I wish it to be distinctly understood,that Ido not limit myself to this exact form or construction of valve,as any other common and well-known form of valve could besubstituted-as, for example, one or two of the oscillating or rotarytype.

17 17 are extensions on the valve near the in ner sides of the endpieces or heads, which form riding-shoes or auxiliary bearing-surfacesin addition to that provided for the valve proper and are at a distancefrom the inner sides of the valve ends not less than the width of theports. By this means an abundant sliding surface is secured, whichprevents rapid wear, and at the same time as the riding-shoes are drawnback far enough on the valve-seat to reach that portion which is welllubricated will act as a distributer and furnish the valveface withlubricant that it Would not otherwise receive, for the reason that thevalvefaces, especially in short travel, do not reach Furtherthe oiledportion of the valve-seat. more, the steam usually blows off the oilfrom Ioo or ends 12 12' of the valve are preferably two packing-stripgrooves 18 18 of even depth. 19 19 are packing-strips properly shapedand arranged in said grooves 18 to make a steamtight joint between thevalve ends and the inner surface of the pressure-plate.

22 22 are springs for forcing the packingstrips against thepressure-plate.

The upper curved surfaces of the valveheads are so constructed andproportioned to be separated from the inner surface of thepressure-plate by such a space as to permit the valve torecede'sufficiently from its valveseat to relieve compression when thevalve ends are in a position to close the ports while the engine isdrifting and no live-steam pressure is in the steam-chest. However, itmay be stated in the use of the auxiliary exhaustvalve orcompression-regulating valve to be presently described the tendency toaccumulate compression is very much less than it would be with theordinary or standard gear and valve.

20 20 are intercepting grooves, one in the lower side of each of thevalve ends 12 12, and which extend nearly the entire width of the valvewithin one-fourth to three-eighths of an inch of each side, one-eighthto onefourth of an inch in depth, and from one-half to three-fourths ofan inch in width. 21 21 are holes drilled through the valve ends andwhich connect the groove 20 with the space between the two strips 19 19in the upper side of each of the valve ends. The purpose of thesegrooves is for intercepting the steam when passing under the valve whenthe port is uncovered, and therefore allow the steam to pass up theholes 21 21 and instantly equalize the pressure between the two stripsand the upper and lower sides of the valve. By this simple constructionand arrangement it will be seen 1 have not only devised a valve whichwill float, but at the same time perfectly balanced, which especiallyadapts the engine for locomotive and high-speed work.

In order to permit the valve to recede from its seat, there is provideda valve stem or rod 23 withv a reduced section 2 1, which passes throughand is smaller than the internal diameter of the tube or centraltie-section 11, thus permitting the valve to be raised or leave its seatwhen compression takes place in the cylinder.

25 25 are the auxiliary exhaust or compression-regulating valves, andwhile I have'shown them of a piston type any other form may be readilysubstituted and one continuous valve construction, as that shown in themain valve 9, or one or more oscillating or rotary valves may be used,if so desired.

26 26 are the short auxiliary ports, which are controlled by thecompression-regulating valves 25 25. As will be seen by reference toFig. 2, the compression-regulating valves are situated adjacent totheinner portion of the cylinder and connect with the outsideexhaust-passages 27 27 ,which lead to the petticoat-pipe connection 28.

29 is the live-steam pipe connection, which by means of passage 30,separated by airspaces 32 32 and between the exhaust-pas sages 27 27,leads the live steam into the space 31 (see Fig. 1) of thevalve-chamber, situated between the two heads or ends 12 12 of the valveand above and below the central tie-section 11.

From the foregoing description of the construction and arrangement oflive-steam ports and exhaust I have devised a cylinder in which thelength of the ports are brought to a minimum, thereby reducing theclearance, radiating-surfaces, the friction of the steam in passing tothe cylinder, and at the same time permitting the short straight portsto be easily cleaned. Furthermore, with this form and arrangement ofcylinder and its ports the live steam is brought in contact with a largeportion of the center of the cylinder, while the exhaust and live steampassages are separated by air-spaces, the live steam being on the insideand the exhaust on the outside, which act as a very effectual insulationagainst the cooling influence of the atmosphere. It will also be noticedthat the live steam within the steam-chest is first insulated by theexhaust-steam and then by an air-space, and only a portion of thecylinder being exposed to atmospheric influences.

The main valve 9 is reciprocated through. the valve stem or rod 23,which is connected to the usual rocker-arm 33 of a valve-gear. Connectedwith and depending from this valve-rod 23 is an arm 35, having anenlargement at its end and so constructed as to have oppositely-disposeddash-pots 3 1 34:, with an opening 36 connecting them for the passage ofa valve-stem 37, connected with the compression-regulating valves 25 25.Supported on said valve-stem 37 are two adjustable pistons 38 38, whichengage right and left hand screw-threads on the valve-stem and cooperatewith the dash-pots 3 1 and 34, respectively, as will presently bedescribed.

While I have herein shown and specifically described pistons anddash-pots for the purpose of operating the compression-regulating valve,the expedient is used, preferably, for the purpose of deadening thesound of impact of the two parts; but I wish it to be understood that asimple and ordinary cam construction could be adopted without departingfrom the invention, or, if so desired, separate and independent meansfrom that which controls the main valve could be made to operate thecompression-regulating valve.

In order to quickly and readily adjust the position of the cams withrespect to the dashpots by separating or bring them closer togetherwhile the engine is in motion, 1 have provided each of the pistons withan integral IIC gear 39 39', which engages with a pinion 40,

' suitably supported and in engagement with the gears 39 39 in allpositions of the compression-regulating valves 25 25. A rod 41, whoserotation may be controlled from the cab, is suitably connected to thepinion 40, so that when the same is rotated it will turn the gears 39 39and adjust the position of the pistons 38 and 38.

The operation of the compression-regulating valves may be accomplishedin many ways; but I have found the above-described arrangement a simpleand ePficient one in that the dash-pots entrap suflicient air whenengaging the piston to prevent a noise or jar.

While I have shown the pinion 4:0 and gears 39 and 39 for adjusting thepistons 38, it can be readily seen that these parts can be omitted andthe engine be made to operate in the same manner after having adjustedthe pistons by hand and locking them by any common and well known means.I wish it also to be understood that any other means may be employed foractuating the compression-regulating valves, so as to preserve therelation of having them close the exhaust after the exhaust by the mainvalve is out off.

The operation of the invention is as follows: Assuming the piston andvalves in the position indicated in Fig. 1, the live steam under thevalve and between its ends passes, by means of the passage between theriding-shoes and the ends of the valve, into the short port 8 into thecylinder back of the piston 2, when the same is forced to the other endof the cylinder. During this travel of the piston the main valvecompletely uncovers the port 8 and cuts ofi on its return at a timeregulated by the valve-gear, the expanded steam at the other end of thecylinder having exhausted through the other port, 8, uncovered by theother end, 12, of the main valve. This movement of the main valve bymeans of the valve-rod 23 and depending rod 35 acts against the cam 38,thereby operating the valve 25, which closes the auxiliary exhaust-ports26 after the exhaust through port 8 has been closed by the main valve12. By this arrangement of pistons and actuating mechanism the auxiliaryexhaust-valves will open simultaneously with or a little later than themain valve, but are made to close for compression much later than themain valve and effect a more efiicient distribution of the steam byavoiding unnecessary back pressure due to the too early closing of themain valve and at the same time having under absolute control thecompression independent of the main valve whereby the clearance of theports and cylinder may be reduced, and consequently effect a greatsaving of steam.

While I have shown and described my engine and valve arrangement beingused in connection with steam, it can be used with the same efficiencyand manner with any other expansible fluid.

Various changes may be made in-the details of my engine and in the meansfor operating or adjusting the valves, and while I have in the foregoingspecification described one form to accomplish the results aimed at yetit will be obvious to those skilled in the art that the specificconstruction and arrangement may be modified in many ways withoutchanging in any way the operation of the mechanism or varying theinvention.

From the detailed description and the mode of operating the same it willbe clearly seen that I have devised an apparatus in which the objectsset out in the statement of invention are fully and efficiently carriedout.

Having now fully described my invention, what I claim as new, and desireto secure by Letters Patent, is

1. A steam-engine comprising a cylinder, a steam-chest, admission andexhaust ports connecting the steam-chest with the cylinder, auxiliaryexhaust-ports connecting the cylinder with the main exhaust, a mainvalve in said steam-chest controlling the admission and exhaust throughthe steam-ports and a compression-regulating valve controlling theauxiliary exhaust-ports.

2. A steam-engine comprising a cylinder, a steam-chest, admission andexhaust ports connecting the steam-chest with the cylinder, auxiliaryexhaust-ports connecting the cylinder with the main exhaust, a mainvalve in 7 said steam-chest. controlling the admission and exhaustthrough the steam-ports, means for balancing the saidmain valve and acompression-regulating valve controlling the auxiliary exhaust-ports. v

3. A locomotive steam-engine comprising a cylinder, short admission andexhaust ports connecting the steam-chest with the cylinder, auxiliaryexhaust-ports connecting the cylinder with the main exhaust, a mainvalve in said steam-chest controlling the admission and exhaust throughthe short steam-ports, means for permitting the said main valve torecede from its seat or float while drifting and acompression-regulating valve controlling the auxiliary exhaust-ports.

4:. A steam-engine comprisinga cylinder, a steamchest,short admissionand exhaust ports connecting the steam-chest with the cylinder,auxiliary exhaust-ports connecting the cylinder with the main exhaust, amain valve having two heads or ends controlling the said short admissionand exhaust ports, a riding strip or surface at each of the two heads orends of the valve and at a distance therefrom not less than the width ofa short admission and exhaust port and a compression-regulating valvecontrolling the auxiliary exhaustports.

5. A steam-engine comprising acylinder, a

steam-chest, short admission and exhaust ports connecting thesteam-chest with the cylinder, auxiliary exhaust-ports connecting thecylinder with the main exhaust, a main valve in said steam-chestcontrolling the admission and exhaust through the short steam-ports, acompression-regulating valve controlling the auxiliary exhaust-ports andmeans connected to the main-valve-operating mechanism for actuating thesaid compression-regulating valve.

6. A steam-engine comprisinga cylinder, a steam-chest, short admissionand exhaust ports connecting the steam-chest with the cylinder,auxiliary exhaust-ports connecting the cylinder with the main exhaust, amain valve in said steam-chest controlling the admission and exhaustthrough the short steam-ports, a compression-regulating valvecontrolling the auxiliary exhaust-ports, means connected to themain-valve-operating mechanism for actuating the saidcompression-regulating valve and means for adjusting the connections tovary the movement of the compression-regulating valve.

7 A steam-engine comprising a cylinder, a steam-chest, short admissionand exhaust ports connecting the steam-chest with the cylinder,auxiliary exhaust-ports connecting the cylinder with the main exhaust, amain valve in said steam-chestcontrolling the admission and exhaustthrough the short steam-ports, means for operating the main valve, acompressionregulating valve controlling the auxiliary exhaust-ports,means for operating the compression-regulating valve and closing theauxiliary exhaustports after the main valve closes the exhaust throughthe short admission and exhaust ports and means for varying the movementof the compression-regulating valve.

8. A steam-engine comprising a cylinder, a steam-chest, a valve-seat inthe steam-chest adjacent to the wall of the cylinder, short admissionand exhaust ports passing through the wall and valve-seat and connectingthe steamchest with the cylinder, a slide-valve on said valve-seatconsisting of a central or tie section, end pieces having surfacesparallel with the line of travel of the valve and at right angles to thecentral or tie section and which control the short steam-ports, a curvedor segmental back on said end pieces, a pressureplate of correspondingsegmental form and covering the slide-valve, means for conducting thelive steam under the pressure-plate and between the end pieces of thevalve, auxiliary exhaust-ports connecting the cylinder with the mainexhaust and a compression-regulating Valve controlling the auxiliaryexhaust-ports.

9. A steam-engine comprising a cylinder, a steam-chest, a valve-seat inthe steam-chest adjacent to the Wall of the cylinder, short admissionand exhaust ports passing through the wall and valve-seat and connectingthe steamchest with the cylinder, a piston slide-valve on saidvalve-seat consisting of a central or tie section, end pieces havingsurfaces parallel with the line of travel of the valve and at rightangles to the central or tie section and which control the short ports,a riding strip or surface provided at each end of the valve at adistance from the inner edges of the valve and pieces not less than thewidth of the ports, a pressure-plate covering the piston slidevalve,means for conducting the live steam under the pressure-plate and betweenthe end pieces of the valve, auxiliary exhaust-ports connecting thecylinder with the main exhaust and a compression-regulating valvecontrolling the auxiliary exhaust-ports.

10. A steam-engine comprising a cylinder, a steam-chest, a valve-seat inthe steam-chest adjacent to the wall of the cylinder, short admissionand exhaust ports passing through the wall and valve-seat and connectingthe steamchest with the cylinder, a piston slide-valve on said seatconsisting of a central or tie section, end pieces having surfacesparallel with the line of travel of the valve and at right angles to thecentral or tie section and which control the short ports, means forbalancing the steam-pressure on the end pieces, a pressure-platecovering the piston slide-valve, means for conducting the live steamunder the pressure-plate and between the end pieces of the valve,auxiliary exhaust-ports connecting the cylinder with the main exhaustand a compression-regulating valve controlling the auxiliaryexhaust-ports.

11. A locomotive steam-engine comprising a cylinder, a steam-chest, avalve-seat in the steam-chest adjacent to the wall of the cylinder,short admission and exhaust ports passing through the wall andvalve-seat and connccting the steam-chest with the cylinder, a pistonslide-valve on said seat consisting of a central or tie section, endpieces having surfaces parallel with the line of travel of the valve andat right angles to the central or tie section and which control theshort ports, means for permitting the piston slide-valve to recede fromits seat or float, a pressure-plate covering the piston slide-valve,means for conducting the live steam under the pressureplate and betweenthe end pieces of the valve, auxiliary exhaust-ports connecting thecylinder with the main exhaust and a compressionregulating valvecontrolling the auxiliary exhaust-ports.

12. A locomotive-engine comprising a cylinder, a steam-chest, avalve-chamber in the steam chest, short admission and exhaust portsconnecting the valve-chamber with the cylinder, a main valve within thesaid valvechamber, an exhaust-chamber surrounding the val ve-chamber,exhaust-passages extending to one side of the cylinder and having theirends connected to the ends of the exhaust-chamber and a mainexhaust-pipe, auxiliary exhaustports on the same side of the cylinder asthe said exhaust-passages and connecting the cylinder with theexhaust-passages, compressionregulating valves controlling the auxiliaryexhaust-ports, a live-steam supply-passage beto partially surround thecylinder and convey the live steam into the valve-chamber.

13. A steam-engine comprising a cylinder, a steam-chest, admission andexhaust ports connecting the steam-chest with the cylinder, auxiliaryexhaust-ports connecting the cylinder with the main exhaust, a mainvalve in said steam-chest controlling the admission and exhaust throughthe steam-ports, means for operating said main valve, acompression-regulating Valve controlling the auxiliary exhaust-ports andmeans for operating the compression-regulating valve.

14. A steam-engine comprising a cylinder, a steam-chest, short admissionand exhaust ports through the wall of the cylinder and connecting thesteam-chest with the cylinder,

auxiliary exhaust-ports connecting the cylin der with the main exhaust,a main valve in said steam-chest controlling the admission and exhaustthrough the said short steam-ports and a compression-regulating valvecontrolling the auxillary exhaust-ports. tween the exhaust-passages andso arranged 15. A steam-engine comprising a cylinder, a steam-chest,short admission and exhaust ports through the wall of the cylinder andhaust through the said short steam-ports,

means for operating the main valve, a compression-regulatingyalvecontrolling the auxiliary exhaust-ports and means for operating thecompression-regulating valve.

In testimony whereof I aflix my signature in presence of two witnesses.

JAMES B. ALLFREE. Witnesses:

A. G. HEGGEM, E. B. HETZEL.

